UK's Prince Harry And Tartan-Clad Meghan Wow Edinburgh

Crowds who had waited hours in the cold outside Edinburgh Castle, which dominates the skyline from a rock in the city centre, were thrilled with the smiling Prince Harry and his American fiancee Meghan Markle

Meghan Markle and Britain's Prince Harry meet members of the public at Edinburgh Castle (Reuters)

EDINBURGH: Prince Harry and his American fiancee Meghan Markle, who was dressed in a Scottish tartan coat, were welcomed enthusiastically in Edinburgh on Tuesday on an official joint visit to Scotland ahead of their marriage in May.

Crowds who had waited hours in the cold outside Edinburgh Castle, which dominates the skyline from a rock in the city centre, were thrilled with the smiling couple.

"They are just amazing, so down to earth and people's people who bring everyone together," said Amanda Scott, from Edinburgh.

Markle wore a blackwatch tartan coat, one of the checked fabrics associated with Scottish traditional dress.

Harry, 33, and Markle, 36, were officially welcomed to the city by the Royal Marines Scotland Band at the castle, where they observed the firing of the one o'clock gun, a tradition that dates back to 1861.

They were also visiting Social Bite, a charity that runs cafes and distributes food to the homeless, as well as employing staff who have been homeless. The eatery has attracted visits from other high-profile names such as actors George Clooney and Leonardo di Caprio.

Meghan Markle meets members of the public during a walkabout on the esplanade at Edinburgh Castle (Reuters)

The royal couple's social work spoke highly of them, Scott's 13-year-old daughter said.

"I think it's great they do all this stuff for charity, that they are in power but they use their power for good," she said.

Harry and Markle were also due to attend a reception at the Palace of Holyroodhouse, meeting youth representatives from several charities.

"They are active in the community and they are not sitting up in a castle somewhere barking orders at people so I think this is a good generation for the royals," said Richard Aylward, a 46-year-old Australian visiting family in Scotland.

Queen Elizabeth's grandson, fifth-in-line to the throne, and Markle, star of the U.S. TV legal drama "Suits", announced their engagement last year and will be married on May 19 at Windsor Castle.